1. Field of the Invention
The present invention relates to a foot and/or exercising device for medical purposes.
2. Description of the Invention
Seriously ill patients who have been at prolonged bedrest have been found to be at risk for the development of deep venous thrombosis. More particularly, patients who have congestive heart failure, those with recent myocardial infarction, patients with malignant disease, and those with various shock syndromes are at greatest risk. Other predisposing conditions are polycythemia vera, dysproteinemias, antithrombin III deficiency, high-dose estrogen treatment as an oral contraceptive, pregnancy, obesity, and sickle cell anemia. Patients more than sixty years old have an increased incidence of deep venous thrombosis compared with those in younger age groups. Varicose veins and prior venous thromboembolic disease also predispose a person to deep venous thrombosis. Postoperative deep venous thrombosis occurs with increased frequency in patients with pelvic, abdominal, and thoracic surgery and in those who have had orthopedic procedures. Posttraumatic deep venous thrombosis is also a major clinical problem, particularly in patients who have been immobilized for prolonged periods and who have any of the other predisposing problems enumerated above.
A number of physical methods for the preventing of deep venous thrombosis in patients at risk are in wide use. All of these methods depend basically on the concept of improving venous hemodynamics and flow to reduce venous stasis in the lower extremeties and thereby inhibit development of deep venous thrombosis. Early ambulation, though not critically tested, is widely accepted as effective prophylaxis. Leg elevation and active and passive leg exercises also have a rational basis for use in reducing deep venous thrombosis. Electrical muscle stimulation intraoperatively has been shown to be effective in reducing deep venous thrombosis but has a number of disadvantages and has not achieved wide clinical application. Properly designed and properly applied elastic compression stockings have been shown in some studies to be effective in prophylaxis and are widely used. Also receiving attention in recent years has been intermittent external pneumatic compression, which has been shown to be effective in the prevention of deep venous thrombosis. Patients with malignant diseases are at increased risk for deep venous thrombosis and do not respond as favorably to physical methods or prophylaxis as patients with nonmalignant diseases. This information is reviewed in greater detail in the publication entitled "Pulmonary Embolism, Mayo Clinic Proc.", 56:161-168, 1981, particularly pages 162 and 165 by Rosenow III et al.
As reflected from the above discussion, U.S. Pat. No. 4,159,111 to Lowth discloses a leg exerciser for medical purposes which includes a treddle apparatus including a base for a pair of foot pedals mounted thereon. It is apparent, however, that this apparatus is of a complex nature regarding the number of elements that are necessary for operative interengagement so as to provide leg exercise for a patient. A similarly complex foot exercising device is shown in U.S. Pat. No. 3,917,261 which includes a pair of foot holders pivotably secured within a housing and which utilizes a powering motor which drives the foot holders by means of rigid actuating links which are driven by eccentric connection to the motor. U.S. Pat. No. 3,022,071 to Malone et al also discloses a complex foot exercising device which includes at least a first and seconds floatingly mounted spring connected to rear faces of each pedal at a point adjacent the heels thereof.